Cognitive impairment has been defined as a decline in one or more of the following domains: short-term memory, attention, orientation, judgment and problem-solving skills, and visuospatial skills. (DSMMD, 4th ed.) Dementia includes the presence of memory loss and a decline in at least one other cognitive domain, as well as functional, social, or occupational impairment. Alzheimer’s disease is an irreversible neurodegenerative disease, the most common cause of dementia in older adults. (For more information refer to https://ajp.psychiatryonline.org/doi/10.1176/ajp.152.8.1228.)
Normal cognitive changes related to driving that occur with aging include:
- Working memory: decline of ability to retain certain information while simultaneously processing other information
- Speed of processing: decrease in speed to organize information into usable patterns and use
- Speed of information retrieval: decrease in speed in locating and retrieving previously learned information
- Decline in ability to focus on selective attention (important information only) and divided attention (ability to divide attention between multiple stimuli at once).
- Executive function, insight often involves knowing what action to take in any given situation, such as planning routes, and age is not always a factor. Insight is essential for self-monitoring personal driving ability.
These domains are evaluated for skills essential in a driving environment.
Cognitive Impairment and Medical Problems
Medical problems can affect the ability of older adults to drive safely, and cognitive impairment, such as dementia, can increase this risk. Medical Professionals can screen for risky driving behaviors among older drivers with cognition problems. During an office visit, they can determine the severity and etiology of the cognitive impairment, using brief tests to determine the level of risk before counseling them and their family members or caregivers about driving tests or other transportation options
Review Patient Driving Status
- Check in with family and caregivers about driving history. A clinician can ask a family member or caregiver what they have observed about the patient’s driving skills, including abnormal driving behaviors, such as crashes, dents on car, difficulty understanding traffic signs, driving too fast or too slow, getting lost in familiar places, and “near misses.”
- Review medical history and review of systems. Check for medical conditions that may directly affect cognition, such as Parkinson’ disease, sleep apnea, substance abuse or depression, as well as history of falls.
- Review medication list. There are potentially driving-impairing medications that may cause cognitive impairment, for example, antidepressants, benzodiazepines, and narcotic analgesics (Pomidor). The American Geriatric Society (AGS) 2019 Beers Criteria update can be useful as a starting point for detecting medications or medication classes to avoid or use with caution for some or all older adults, as many of these are relevant to safe driving. In addition, the AAA LongROAD Study identified potentially inappropriate medications (PIMs) most commonly used by older drivers that have been linked to driving impairment and increased crash risk, including benzodiazepines (e.g, Diazepam or Valium, typically used to treat anxiety, insomnia and seizures, and to relax the muscles), nonbenzodiazepine, hypnotics, antidepressants, and first-generation antihistamines.
- Identify medical conditions that may indirectly affect cognition, such as diabetes, congestive heart failure, cardiac arrhythmia, syncope/orthostatic hypotension and valvular disease. (Pomidor)
Administer Tests to Measure Cognitive Skills
Several screening tools (available in the Appendix to the Primary care providers Guide, p. 267, that measure cognitive skills can be administered by a member of the clinical team:
- Montreal Cognitive Assessment (MoCA): Screening tool, available in multiple languages and takes only 10-15 minutes to administer.
- Trails B: Assesses working memory, visual processing, visuospatial skills, selected and divided attention, and psychomotor coordination. Poor performance on this test is associated with poor driving performance.
- Clock-drawing: May assess long-term memory, sort-term memory, visual perception, visuospatial skills, selective attention, abstract thinking, and executive functioning.
- Maze: Assesses visual perception, visuospatial skills, abstract thinking, and executive skills. The Snellgrove Maze, a one-page cognitive screen for driving competence was validated with older adults with mild cognitive impairment or early dementia. (Pomidor)
Poor performances on these types of tests have been correlated with poor driving outcomes in older adults with dementia, including increased crash rates and impaired performance in driving simulations and on-the-road tests. (Carr article)
Assess Level of Dementia
Medical Professionals tend to base their decisions about safe driving on the severity of dementia rather than on the presence of dementia itself. The Clinical Dementia Rating (CDR) is an evidence-based tool that can be used to assess the level of dementia of the patient and can be used as a guideline for clinicians. In addition, the Alzheimer’s Association assists families with education and counseling about driving issues.
- Next Steps: 4 R’s for Medical Professionals (Pomidor)
Identify any medical conditions and or medications causing increased risk of cognitive impairment; treat or reduce medical risks and/or refer for additional evaluation and treatment from clinical specialists.
- Referral: If driving deficits still exist after medical conditions have been treated, refer to an occupational therapist for assessment of functional abilities and mobility support; driving rehabilitation specialist for further evaluation and treatment; and/or social worker for assessment of transportation needs, caregiver support, and training recommendations.
- Resources: Provide information and referral to local and national resources to patients and caregivers to support continued older adult mobility, such as National Highway Traffic Safety Administration and others listed beginning on p. 176 of the Primary care providers Guide.
- Restriction: For the older adult with persistent driving deficits, recommend restricted driving, cessation of driving until further recovery, or permanent license restriction if recovery is unlikely. Review your state’s licensing and license renewal criteria and any mandates for healthcare professionals to report unsafe drivers or those with specific medical conditions to the driver licensing agency of your state. A database of driver licensing policies/practices can be found at http://lpp.seniordrivres.org/lpp/index.cfm?selection=visionreqs.